Faulty Contactors in AC

Air Conditioners

As a homeowner, it’s essential to be familiar with common air conditioner issues, especially during the hot summer months. One such problem that can affect your AC system’s performance is faulty contactors. Here, we will delve into the details of this issue and provide you with effective solutions to keep your air conditioner running smoothly. If you require professional assistance, don’t hesitate to reach out to ALP Heating at 647-972-8714 or email us at [email protected].

The Role of Contactors in Air Conditioners

A contactor is an essential electrical component in your air conditioner that functions as a switch to control the flow of electricity to various parts of the system. This includes the compressor, condenser fan motor, and evaporator fan motor. The contactor ensures that the appropriate amount of power is supplied to each component for optimal operation. When the thermostat calls for cooling, the contactor engages, allowing the electrical current to flow. Once the desired temperature is reached, the contactor disengages, cutting off power to the components.

Signs of Faulty Contactors in AC

Faulty contactors in AC can lead to several issues, including reduced cooling efficiency, intermittent operation, or complete system failure. Here are some common signs that your contactor may be malfunctioning:

  1. AC unit fails to start or stops intermittently: If your air conditioner struggles to start or stops working unexpectedly, a faulty contactor could be the culprit. This may be due to worn-out contact points or a damaged coil that prevents the contactor from engaging or disengaging properly.
  2. Unusual noises: A humming or buzzing sound coming from your AC unit may indicate a malfunctioning contactor. This can occur when the contact points are dirty, corroded, or pitted, causing them to stick together or fail to make proper contact.
  3. Higher energy bills: If your energy consumption has increased significantly without any apparent reason, it might be due to a faulty contactor that’s causing your AC system to run continuously or inefficiently.
  4. Visible damage: Inspect your contactor for signs of damage, such as burnt or pitted contact points, melted plastic casing, or a discoloured coil. These can all indicate a faulty contactor that needs replacement.

Solutions for Faulty Contactors in AC

When dealing with faulty contactors in AC, consider the following solutions:

  1. Clean the contact points: If the contact points are dirty or mildly corroded, cleaning them with a fine sandpaper or emery cloth can help restore proper function. However, if they are severely damaged or worn, it’s best to replace the contactor.
  2. Check the coil voltage: Use a multimeter to verify if the coil is receiving the correct voltage. If the voltage is too low, it can prevent the contactor from engaging. In this case, you may need to consult a professional to identify and fix the underlying issue.
  3. Replace the contactor: If cleaning the contact points or checking the coil voltage doesn’t resolve the issue, it’s likely that the contactor needs to be replaced. It’s best to hire a licensed technician to handle this task, as improper installation can lead to further damage or even electrical hazards.


Faulty contactors in AC can lead to a variety of common air conditioner issues, including decreased cooling efficiency, system failures, and increased energy consumption. By understanding the signs of a faulty contactor and taking appropriate measures to address the problem, you can ensure that your air conditioner continues to function optimally.

Regular maintenance and inspections by qualified technicians can help identify potential problems early on and prevent costly repairs or system breakdowns. If you suspect a faulty contactor in your AC or require assistance with any other air conditioner issues, don’t hesitate to contact ALP Heating. Our team of skilled professionals is dedicated to providing exceptional service and keeping your home comfortable all year round.

Remember, being proactive about your air conditioner’s maintenance and repair can extend its lifespan, reduce the risk of unexpected breakdowns, and ensure optimal performance. Don’t wait until you experience issues – schedule regular check-ups and inspections with ALP Heating to keep your AC system in peak condition. Trust us to be your go-to experts for all your air conditioner needs, from detecting and solving faulty contactors to addressing any other common issues that may arise.

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